I/O System S900
Communication Interface for PROFIBUS DP, CI920
3BDD010422R0101
35
Additionally, the system is provided with a simulation (forcing) option
allowing you to perform important servicing and commissioning tasks. The
simulation function serves for:
•
testing the applications in the PLC or the OCS,
•
simulating the actors if no PLC/OCS is available yet,
•
avoiding unwanted error messages in the case of signal failures that may
occur when a defective module is replaced.
Indicator LEDs
The CI920 has five LEDs on its front panel which indicate the following
states.
Table 4-5 CI920 LEDs
LED
Description
1 (PW)
off
No power supply
green Power
ok
red
Serious error (e.g. checksum error in ROM)
2 (CA)
off
CAN not used
yellow
CAN
ready
red CAN
error
3 (PB)
off
Slave is waiting for parameters / configuration data
yellow
Slave in DataExchange state
red
DP error, outputs on failsafe
red blinking
Static diagnostics, outputs on failsafe
4 (RD)
off
CI920 is passive
yellow
CI920
active
yellow
blink.
CI920
active,
redundant CI920 not ready
5 (FD)
off
Configuration and parameters o.k.
red
blinking
Configuration or parameter error
PROFIBUS - diagnostics
Functional principle
When the slave is in the DataExchange status, it responds to the master's
output data telegram with input data telegrams. The slave can enter special
data in the telegram header to inform the master about existing diagnostic
data. S900 reports all incoming and outgoing errors to the master, which then
fetches the diagnostic buffer data with the next telegram. With a 25 ms pause